With the development of semiconductor technology the degree of memory integration has been increased, and thus an IC card now can be applied to a numerical control apparatus, a PC (programmable controller) and the like as an external memory. In practice, an IC card reader is used to read the IC card and write data thereto. In this process, the IC card is manually inserted into and withdrawn from a connector by hand or by using a fitting or the like provided at the connector.
An IC card reader applied to a numerical control apparatus and the like is often used in an adverse environment, such as in a metal processing factory and the like, and thus must be made airtight to protect electronic components such as semiconductors accommodated therein. Nevertheless, the conventional IC card reader must have an opening for use as an insertion port, and an IC card reader enabling an IC card to be inserted into and withdrawn from the reader while maintaining the interior thereof in an airtight condition is not known in the prior art. Although a non-contact type IC card has been disclosed in an attempt to solve this problem, the cost thereof is very high.